Diannexin Can Ameliorate Acute Respiratory Distress Syndrome in Rats by Promoting Heme Oxygenase-1 Expression.

BACKGROUND: The recombinant protein diannexin can inhibit platelet-mediated events, which contribute to acute respiratory distress syndrome (ARDS). Here, we investigated the effect of diannexin and its effect on heme oxygenase-1 (HO-1) in ARDS. METHODS: A total of 32 rats were randomized into sham, ARDS, diannexin (D), and diannexin+HO-1 inhibitor (DH) groups. Alveolar-capillary permeability was evaluated by testing the partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) ratio, lung wet/dry weight ratio, and protein levels in the lung. Inflammation was assessed by measuring cytokine levels in the bronchial alveolar lavage fluid (BALF) and serum and nuclear factor-κB (NF-κB) in the lung tissue. Inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and myeloperoxidase (MPO) were measured to evaluate the oxidative stress response. Lung tissue pathology and apoptosis were also evaluated. We measured HO-1 expression in the lung tissue to investigate the effect of diannexin on HO-1 in ARDS. RESULTS: Compared with the ARDS group, diannexin improved PaO2/FiO2, lung wet/dry weight ratio, and protein levels in the BALF and decreased levels of cytokines and NF-κB in the lung and serum. Diannexin inhibited the oxidative stress response and significantly ameliorated pathological lung injury and apoptosis. The partial reversal of diannexin effects by a HO-1 inhibitor suggests that diannexin may promote HO-1 expression to ameliorate ARDS. CONCLUSIONS: We showed that diannexin can improve alveolar-capillary permeability, inhibit the oxidative stress response and inflammation, and protect against ARDS-induced lung injury and apoptosis.

Lipoxin A4 Reduces Ventilator-Induced Lung Injury in Rats with Large-Volume Mechanical Ventilation.

Ventilator-induced lung injury (VILI) is a severe and inevitable complication in patients who require mechanical ventilation (MV) for respiratory support. Lipoxin A4 is an endogenous anti-inflammatory and antioxidant mediator. The present study determined the effects of lipoxin A4 on VILI. Twenty-four rats were randomized to the sham, VILI, and lipoxin A4 (LX4) groups. The rats in the VILI and LX4 groups received large-volume MV for 4 hours to simulate VILI. Capillary permeability was evaluated using the PaO2/FiO2 ratio, lung wet/dry weight ratio, and protein level in the lung. VILI-induced inflammation was assessed by measuring cytokines in serum and lung tissue, the expression and activity of NF-κB, and phosphorylated myosin light chain. The oxidative stress response, lung tissue injury, and apoptosis in lung tissue were also estimated, and the expression of apoptotic proteins was examined. MV worsened all of the indices compared to the sham group. Compared to the VILI group, the LX4 group showed significantly improved alveolar-capillary permeability (increased PaO2/FiO2 and decreased wet/dry weight ratios and protein levels), ameliorated histological injury, and reduced local and systemic inflammation (downregulated proinflammatory factors and NF-κB expression and activity). Lipoxin A4 notably inhibited the oxidative stress response and apoptosis and balanced apoptotic protein levels in lung tissue. Lipoxin A4 protects against VILI via anti-inflammatory, antioxidant, and antiapoptotic effects.

Ac2-26 Alleviates Brain Injury after Cardiac Arrest and Cardiopulmonary Resuscitation in Rats via the eNOS Pathway.

BACKGROUND: Brain injury is the leading cause of death following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Ac2-26 and endothelial nitric oxide synthase (eNOS) have been shown to reduce neuroinflammation. This study is aimed at determining the mechanism by which Ac2-26 protects against inflammation during brain injury following CA and CPR. METHODS: Sixty-four rats were randomized into sham, saline, Ac2-26, and Ac2-26+L-NIO (endothelial nitric oxide synthase (eNOS) inhibitor) groups. Rats received Ac2-26, Ac2-26+L-NIO, or saline after CPR. Neurologic function was assessed at baseline, 24, and 72 hours after CPR. At 72 hours after resuscitation, serum and brain tissues were collected. RESULTS: Blood-brain barrier (BBB) permeability increased, and the number of surviving neurons and neurological function decreased in the saline group compared to the sham group. Anti-inflammatory and proinflammatory factors, neuron-specific enolase (NSE) levels, and the expression of eNOS, phosphorylated (p)-eNOS, inducible nitric oxide synthase (iNOS), and oxidative stress-related factors in the three CA groups significantly increased (P < 0.05). BBB permeability decreased, and the number of surviving neurons and neurological function increased in the Ac2-26 group compared to the saline group (P < 0.05). Ac2-26 increased anti-inflammatory and reduced proinflammatory markers, raised NSE levels, increased the expression of eNOS and p-eNOS, and reduced the expression of iNOS and oxidative stress-related factors compared to the saline group (P < 0.05). The effect of Ac2-26 on brain injury was reversed by L-NIO (P < 0.05). CONCLUSIONS: Ac2-26 reduced brain injury after CPR by inhibiting oxidative stress and neuroinflammation and protecting the BBB. The therapeutic effect of Ac2-26 on brain injury was largely dependent on the eNOS pathway.

Annexin A1 peptide Ac2-26 mitigates ventilator-induced lung injury in acute respiratory distress syndrome rats and partly depended on the endothelial nitric oxide synthase pathway.

PURPOSE: Although mechanical ventilation is an essential support for acute respiratory distress syndrome (ARDS), ventilation also leads to ventilator-induced lung injury (VILI). This study aimed to estimate the effect and mechanism of Annexin A1 peptide (Ac2-26) on VILI in ARDS rats. METHODS: Thirty-two rats were randomized into the sham (S), mechanical ventilation (V), mechanical ventilation/Ac2-26 (VA), and mechanical ventilation/Ac2-26/L-NIO (VAL) groups. The S group only received anesthesia, and the other three groups received endotoxin and then ventilation for 4 h. Rats in the V, VA and VAL groups received saline, Ac2-26, and A c2-26/N5-(1-iminoethyl)-l-ornithine (L-NIO), respectively. RESULTS: All indexes deteriorated in the V, VA and VAL groups compared with the S group. Compared with V group, the PaO2/FiO2 ratio was increased, but the wet-to-dry weight ratio and protein levels in bronchoalveolar lavage fluid were decreased in the VA group. The inflammatory cells and proinflammatory factors were reduced by Ac2-26. The oxidative stress response, lung injury and apoptosis were also decreased by Ac2-26 compared to V group. All improvements of Ac2-26 were partly reversed by L-NIO. CONCLUSIONS: Ac2-26 mitigates VILI in ARDS rats and partly depended on the endothelial nitric oxide synthase pathway.

Inhibition of DNA methylation attenuates lung ischemia-reperfusion injury after lung transplantation.

OBJECTIVE: DNA methylation plays an important role in inflammation and oxidative stress. This study aimed to investigate the effect of inhibiting DNA methylation on lung ischemia-reperfusion injury (LIRI). METHODS: We adopted a completely random design for our study. Thirty-two rats were randomized into the sham, LIRI, azathioprine (AZA), and pluripotin (SC1) groups. The rats in the LIRI, AZA, and SC1 groups received left lung transplantation and intravenous injection of saline, AZA, and SC1, respectively. After 24 hours of reperfusion, histological injury, the arterial oxygen partial pressure to fractional inspired oxygen ratio, the wet/dry weight ratio, protein and cytokine concentrations in lung tissue, and DNA methylation in lung tissue were evaluated. The pulmonary endothelium that underwent hypoxemia and reoxygenation was treated with AZA or SC1. Endothelial apoptosis, chemokines, reactive oxygen species, nuclear factor-κB, and apoptotic proteins in the endothelium were studied. RESULTS: Inhibition of DNA methylation by AZA attenuated lung injury, inflammation, and the oxidative stress response, but SC1 aggravated LIRI injury. AZA significantly improved endothelial function, suppressed apoptosis and necrosis, reduced chemokines, and inhibited nuclear factor-κB. CONCLUSIONS: Inhibition of DNA methylation ameliorates LIRI and apoptosis and improves pulmonary function via the regulation of inflammation and oxidative stress.

Lipoxin A4 attenuates the lung ischaemia reperfusion injury in rats after lung transplantation.

BACKGROUND: Lung ischaemia reperfusion injury (LIRI) is the major cause of primary lung dysfunction after lung transplantation. Lipoxin A4 inhibits the oxidative stress and inflammation. This study aimed to evaluate the potential protective effect of lipoxin A4 on LIRI in rats. METHODS: SD (Sprague-Dawley) rats were randomised into the sham, LIRI and LA4 groups. Rats in the sham group received anaesthesia, thoracotomy and intravenous injection of saline, while those in the LIRI or LA4 group received left lung transplantation and intravenous injection of saline or lipoxin A4, respectively. After 24 h of reperfusion, the PaO2/FiO2 (Partial pressure of O2 to fraction inspiratory O2), wet/dry weight ratios and protein levels in lungs were measured to assess the alveolar capillary permeability. The oxidative stress response and inflammation were examined. The histological and apoptosis analyses of lung tissues were performed via HE staining (Haematoxylin-eosin staining) and TUNEL assay, respectively. The effects of lipoxin A4 on the endothelial viability and tube formation of hypoxaemia and reoxygenation-challenged rat pulmonary microvascular endothelium cells were determined. RESULTS: Lipoxin A4 significantly ameliorated the alveolar capillary permeability, reduced the oxidative stress and inflammation in transplanted lungs. The histological injury and apoptosis of lung tissues were also alleviated by lipoxin A4. In vitro lipoxin A4 treatment promoted the endothelial tube formation and improved the endothelial viability. CONCLUSION: Lipoxin A4 protects LIRI after lung transplantation in rats, and its therapeutic effect is associated with the properties of anti-inflammation, anti-oxidation, and endothelium protection.Key messages:Lung transplantation is a treatment approach for the patients with lung disease.LIRI is the major cause of postoperative primary lung dysfunction.Lipoxins A4 exhibits strong anti-inflammatory properties.

Endothelial colony-forming cells reduced the lung injury induced by cardiopulmonary bypass in rats.

BACKGROUND: Cardiopulmonary bypass (CPB) results in severe lung injury via inflammation and endothelial injury. The aim of this study was to evaluate the effect of endothelial colony-forming cells (ECFCs) on lung injury in rats subjected to CPB. METHODS: Thirty-two rats were randomized into the sham, CPB, CPB/ECFC and CPB/ECFC/L-NIO groups. The rats in the sham group received anaesthesia, and the rats in the other groups received CPB. The rats also received PBS, ECFCs and L-NIO-pre-treated ECFCs. After 24 h of CPB, pulmonary capillary permeability, including the PaO2/FiO2 ratio, protein levels in bronchoalveolar lavage fluid (BALF) and lung tissue wet/dry weight were evaluated. The cell numbers and cytokines in BALF and peripheral blood were tested. Endothelial injury, lung histological injury and apoptosis were assessed. The oxidative stress response and apoptosis-related proteins were analysed. RESULTS: After CPB, all the data deteriorated compared with those obtained in the S group (sham vs CPB vs CPB/ECFC vs CPB/ECFC/L-NIO: histological score 1.62 ± 0.51 vs 5.37 ± 0.91 vs 3.37 ± 0.89 vs 4.37 ± 0.74; PaO2/FiO2 389 ± 12 vs 233 ± 36 vs 338 ± 28 vs 287 ± 30; wet/dry weight 3.11 ± 0.32 vs 6.71 ± 0.73 vs 4.66 ± 0.55 vs 5.52 ± 0.57; protein levels in BALF: 134 ± 22 vs 442 ± 99 vs 225 ± 41 vs 337 ± 53, all P < 0.05). Compared to the CPB treatment, ECFCs significantly improved pulmonary capillary permeability and PaO2/FiO2. Similarly, ECFCs also decreased the inflammatory cell number and pro-inflammatory factors in BALF and peripheral blood, as well as the oxidative stress response in the lung tissue. ECFCs reduced the lung histological injury score and apoptosis and regulated apoptosis-related proteins in the lung tissue. Compared with the CPB/ECFC group, all the indicators were partly reversed by the L-NIO. CONCLUSIONS: ECFCs significantly reduced lung injury induced by inflammation after CPB.

Expression of miR-23a and miR-135 and tumor markers in gastric cancer patients and the significance in diagnosis.

Correlation between the expression of miR-23a and miR-135 and tumor markers in gastric cancer patients and their significance in diagnosis was investigated. A total of 78 patients with gastric cancer admitted to Dongying People's Hospital from July 2015 to June 2017 were enrolled, and 80 healthy patients were selected as the control group during the same period. The expression levels of miR-23a and miR-135 in the serum of the two groups were detected by RT-qPCR, and the expression levels of tumor markers CEA and carbohydrate antigen 199 (CA199) were detected by ELISA. The receiver operating characteristic curve and area under the curve (AUC) were used to evaluate the diagnostic efficacy of miR-23a and miR-135 as diagnostic indicators. There was no significant difference between the observation and the control group (P>0.05). The expression levels of miR-23a and miR-135 in the observation group were significantly higher than those in the control group (P<0.05). The expression levels of CEA and CA199 in serum of patients in the observation group were significantly higher than those in the control group (P<0.05). Pearson's correlation test showed that the expression levels of miR-23a and miR-135 were positively correlated with CEA and CA199 (P<0.05). The specificity, sensitivity and AUC of miR-23a in the diagnosis of gastric cancer were 67.95, 87.50 and 0.805%, respectively. The specificity, sensitivity and AUC of miR-135 in the diagnosis of gastric cancer were 73.08, 82.50 and 0.824%, respectively. Both could be used in the diagnosis of gastric cancer. In conclusion, miR-23a and miR-135 are highly expressed in gastric cancer patients and positively correlated with tumor markers, which can be used in diagnosis for gastric cancer.